Abstract

New oil discoveries in the southwest area of Bohai Bay by CNOOC Limited-Tianjin and other international oil companies are mostly found in the Middle Miocene Minghuazhen Formation. The Minghuazhen reservoirs are dominated by fluvial channels and shallow lacustrine and deltaic systems. On seismic, fluvial channels are often difficult to follow, and a terrestrial succession such as in the Minghuazhen Formation typically lacks continuous reflections to trace on seismic data. These depositional facies, along with complex postdepositional faulting, makes seismic interpretation and reservoir characterization of this field very difficult. Due to these complications, many development wells may miss penetrating the main pay by very small distances. The interpretation workflows presented in this paper were used to characterize and locate channel distributions. As a result, over 20 infill well locations were proposed and water-injection selections were optimized so that each injection well could effectively penetrate multiple producing sands (Feng et al., 2007).